Apparatuses and methods for negative pressure wound therapy with switchable fluid management

Abstract

Disclosed embodiments relate to wound therapy apparatuses and methods for use in negative pressure wound therapy (NPWT). Such wound therapy apparatuses and methods may reduce maceration during NPWT. The wound therapy apparatus may include a porous hydrophobic layer surrounded by a hydrophilic ring. The hydrophilic ring may serve to prevent passage of liquid while negative pressure is applied to the wound, but allow liquid passage to an absorbent ring when negative pressure is no longer applied. A transmission layer may also be included, underlying the absorbent layer.

1 - 18 . (canceled) 
     
     
         19 . An apparatus to provide negative pressure to a wound site, comprising:
 a hydrophilic manifold positioned around a hydrophobic manifold configured to transmit negative pressure to a wound site, the hydrophilic manifold configured to prevent fluid from the wound site from traveling to the hydrophobic manifold when negative pressure is applied and allow fluid travel from the wound site to the hydrophobic manifold when negative pressure is not being applied.   
     
     
         20 . The apparatus of  claim 19 , further comprising a cover layer. 
     
     
         21 . The apparatus of  claim 20 , wherein the cover layer comprises an aperture. 
     
     
         22 . The apparatus of  claim 21 , further comprising a fluidic connector configured to transmit negative pressure from a negative pressure source to the wound site. 
     
     
         23 . The apparatus of  claim 19 , further comprising a transmission manifold positioned around the hydrophilic manifold. 
     
     
         24 . The apparatus of  claim 19 , further comprising an absorbent manifold positioned around the hydrophilic manifold. 
     
     
         25 . The apparatus of  claim 19 , further comprising a transmission manifold positioned around the hydrophilic manifold and an absorbent manifold positioned over the hydrophilic manifold. 
     
     
         26 . The apparatus of  claim 19 , further comprising a wound contact layer positioned beneath the hydrophobic manifold and the hydrophilic manifold. 
     
     
         27 . The apparatus of  claim 26 , wherein the wound contact layer is perforated. 
     
     
         28 . The apparatus of  claim 23 , wherein the transmission manifold comprises a material having a three-dimensional structure. 
     
     
         29 . The apparatus of  claim 19 , wherein the hydrophobic manifold comprises a hydrophobic foam. 
     
     
         30 . The apparatus of  claim 19 , wherein the hydrophilic manifold comprises hydrophilic foam. 
     
     
         31 . The apparatus of  claim 19 , wherein the hydrophilic manifold comprises polyvinyl alcohol. 
     
     
         32 . A method for providing negative pressure to a wound site, comprising:
 positioning a wound dressing over a wound, the wound dressing comprising a hydrophilic manifold positioned around a hydrophobic manifold; and   applying negative pressure to the wound site via the wound dressing, the hydrophilic manifold configured such that fluid from the wound site travels to the hydrophobic manifold when negative pressure is applied but fluid travel from the wound site to the hydrophobic manifold is prevented when negative pressure is not being applied.   
     
     
         33 . The method of  claim 32 , wherein the wound dressing comprises a cover layer. 
     
     
         34 . The method of  claim 33 , wherein the cover layer comprises an aperture. 
     
     
         35 . The method of  claim 34 , wherein the wound dressing comprises a fluidic connector configured to transmit negative pressure from a negative pressure source to the wound site. 
     
     
         36 . The method of  claim 32 , wherein the wound dressing comprises a transmission manifold positioned around the hydrophilic manifold. 
     
     
         37 . The method of  claim 32 , wherein the wound dressing comprises an absorbent manifold positioned around the hydrophilic manifold. 
     
     
         38 . The method of  claim 32 , wherein the wound dressing comprises a transmission manifold positioned around the hydrophilic manifold and an absorbent manifold positioned over the hydrophilic manifold.